The Imaging Core will provide the scientific and technical expertise needed to fulfill all of the CT and MR imaging needs of the Projects. Providing all imaging services through a single core will avoid duplication of effort regarding Human Studies and regulatory issues, development of scanning protocols, subject management during scanning, and image analysis techniques. Image analysis methods will focus on the quantification of emphysema for both CT and MR, and also airway and airway wall dimensions with CT. Performing all procedures through a single Core will insure consistent imaging and analysis methodology among the Projects, facilitating comparison and correlation of imaging data. The Imaging Core will be comprised of individuals that have been part of a multidisciplinary team (which includes radiologists, physicists, pulmonologists, pathologists, and surgeons) involved in the CT and He MR evaluation of COPD that dates back over seven years. Our experience with the use of these imaging techniques began with the characterization of patients with severe COPD in the Lung Volume Reduction Surgery program at our institution (1-7). It has involved investigations into the impact of technical factors on CT measurements of lung attenuation (8-10), technical factors involved in 3He MR imaging (11-13), and evaluation of the lung microstructure with 3He MR (14). We have performed emphysema-related quantitative analysis of CT scans in over 200 patients, imaged more than 50 subjects with 3He MR (including 33 with advanced COPD), and imaged more than 30 explanted lung specimens with both CT and 3He MR in ongoing studies. Services provided by the Core will include: assistance with Human Studies and regulatory issues; development and implementation of scanning and image reconstruction protocols;production of hyperpolarized 3He gas for MR imaging;MR imaging coil design and construction;performance of CT and MR scans;clinical interpretation of CT scans;image processing and analysis;archiving of images and raw data; and assistance with image deidentification as needed. Project 1 will use the Imaging Core for CT and MR imaging, image analysis, and associated services. Project 3 will use the Core for CT imaging, image analysis, and associated services, and for analysis of existing CT scans of potential subjects for the presence emphysema. Projects 4 and 5 will use the Imaging Core for CT imaging, image analysis, and associated services.